地面效应对直流输电线路可听噪声空间传播特性的影响

Effect of Ground on the Space Propagation Characteristics of Audious Noise in HVDC Transmission Lines

直流线路可听噪声问题是导线架设结构及参数选型的主要影响因素,研究直流输电线路可听噪声的特性及空间传播规律,对于准确预测可听噪声的空间分布及建设满足环保要求的直流线路具有重要意义。因此,从声波基本方程出发,根据地面上方点声源在空间上产生的声压的计算公式,将直流输电线路看成沿导线离散分布的点声源的集合,认为线路在空间产生的噪声是各个声源叠加后的综合效应,计算中考虑了地面的影响。根据这个模型分析了不同地面流阻参数对线路可听噪声的影响规律。通过仿真分析可以得到如下结论:考虑地面的影响会增强线路在空间中产生的可听噪声声压级,地面流阻越大则这种增强作用越强;考虑地面的反射影响后,声压的幅值也会受到影响;这会导致可听噪声声压级在垂直线路方向上的分布存在一定的波动,实际现场测量时需要考虑地面的影响。

The audible noise generated by corona in DC transmission lines is always the main influence factor for determining the structure and parameters of conductors.Studying the characteristics of audible noise in HVDC transmission lines and its spatial propagation law is of great significance for accurately predicting the spatial distribution of audible noise and building HVDC lines that meet the requirements of environmental protection.Based on the basic equation of sound wave and the expression of sound pressure of half-space point source,the audible noise from the transmission line can be regarded as the comprehensive effects of audible noise from multiple point sound sources on the conductor..Then the influence of different ground forms on the distribution of audible noise in HVDC transmission line is discussed.The simulated results show that the ground effect on HVDC line is significant.The spatial distribution of road audible noise is strengthened,and the harder the ground is,the more significant the enhancement is.The ground effect will not only affect the amplitude of sound pressure,but also the phase of sound pressure.Considering the influence of ground effect,the spatial distribution f audible noise along the vertical direction o will fluctuate.The influence of the ground should be considered in the measurement of audible noise in real condition.